Descriptive Mineralogy Non-Silicates:
description
Transcript of Descriptive Mineralogy Non-Silicates:
Descriptive Mineralogy Non-Silicates:
Carbonates
Classification of the Minerals• Non-Silicates
– Native Elements
–Halides– Sulfides– Carbonates– Sulfates– Phosphates– Oxides– Hydroxides
• Silicates– Orthosilicates– Sorosilicates– Cyclosilicates– Chain Silicates– Layer Silicates– Tektosilicates
Carbonates • Calcite Group• Aragonite Group• Dolomite Group• Other carbonates
Carbonate Periodic Table
Calcite Group
• Calcite CaCO3
• Magnesite MgCO3
• Siderite FeCO3 • Rhodochrosite MnCO3
• Smithsonite ZnCO3
Calcite Structure
• Space Group R-3c
• Divalent cation radius < 1.00Å
Calcite CaCO3
Calcite CaCO3
Occurrence: Sedimentary: Detrital and Evaporite limestones
Metamorphic: Marble
Low temperature hydrothermal.
Igneous: Carbonatites, Kimberlites
Uses: Building stone, Sculpture, Gravel and paving
Acid mine drainage mitigation
Rhodochrosite MnCO3
Occurrence: Low T Hydrothermal
Uses: Mineral Specimens
Siderite FeCO3Occurrence:Low temperature
hydrothermal.
Use; Minor ore of Fe
Magnesite MgCO3
Occurrence: olivine weathering
Uses: Chalk CO2 Sequestration?
Smithsonite ZnCO3
Occurrence: Oxidized Hydrothermal (after sphalerite)
Uses: Minor ore of Zn
Aragonite Group
• Aragonite CaCO3
• Strontianite CaCO3 • Witherite BaCO3
• Cerussite PbCO3
Aragonite Structure
• Space Group Pbnm
• Cation Radius > 1.00Å
Aragonite CaCO3
Occurrence: High pressure rocks
Some shells
Boiler scale
Uses: None
Strontianite SrCO3
Occurrence: Low T Hydrothermal
Uses: Principal source of Sr (used in fireworks, ammunition, flares)
Witherite BaCO3
Occurrence: Low T Hydrothermal
Uses: Rat Poison
Witherite transforms at RT from orthorhombic to trigonal
• Witherite (BaCO3)
• 0 GPa 8.0 GPa
Cerussite PbCO3
Occurrence: Oxidized Hydrothermal
Uses: Minor ore of Pb
Dolomite Group
• Dolomite CaMg(CO3)2
• Ankerite CaFe(CO3)2
Dolomite CaMg(CO3)2
Occurrence: Sedimentary, Igneous (carbonantites)
Uses: None
Other Carbonates• Malachite Cu2(CO3)(OH)2
• Azurite Cu3(CO3)2(OH)2
• Bastnasite CeCO3F
• Bastnasite REECO3F
Malachite Cu2CO3(OH)2
Occurrence: Low T Hydrothermal Supergene Cu
Uses: Minor ore of Cu, gems and ornaments
Azurite Cu3(CO3)2(OH)2
Occurrence: Low T Hydrothermal Supergene Cu
Uses: Minor ore of Cu, gems and ornaments
Bastnasite CeCO3F
Occurrence: Pegmatite
Uses: Principal Source of Rare Earth Elements
Bastnasite CeCO3F
Carbonate Periodic Table
Gossans are Oxidized Hydrothermal Deposits